The Stochastic Gravitational Wave Background from the Single-Degenerate Channel of Type Ia Supernovae

We demonstrate that the integrated gravitational wave signal of Type Ia supernovae (SNe Ia) in the single-degenerate channel out to cosmological distances gives rise to a continuous background to spaceborne gravitational wave detectors, including the Big Bang Observer (BBO) and Deci-Hertz Interferometer Gravitational wave Observatory (DECIGO) planned missions. This gravitational wave background from SNe Ia acts as a noise background in the frequency range 0.1 - 10 Hz, which heretofore was thought to be relatively free from astrophysical sources apart from neutron star binaries, and therefore a key window in which to study primordial gravitational waves generated by inflation. While inflationary energy scales of $\gtrsim 10^{16}$ GeV yield inflationary gravitational wave backgrounds in excess of our range of predicted backgrounds, for lower energy scales of $\sim10^{15}$ GeV, the inflationary gravitational wave background becomes comparable to the noise background from SNe Ia.